Caisson



C. GOODMAN Dec. 25, 1951 CAISSON 4 Sheets-Sheet 1 Filed Dec. 19, 1947 FIG. l.

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through the air lock 3l and the connecting shaftway 32. With such a compressed air chamber men with their tools enter and leave through the locks 3|.

Excavation of the bottom is done by these men under air pressure and all the material is likewise removed through the locks 3l and shaftways 32 provided by means of buckets or similar devices which are loaded by the men in the working chamber 30. Of course, the working chamber 30 is placed under sufficient air pressure to balance the hydrostatic head 33 and thereby keep the excavation dry so that men can work at the bottom.

In the open dredged caisson the entire dredge wells 26, 21 and 28 are left completely open (Fig. 2). Excavation is carriedon from above, usually by means of grab buckets 34. Material is removed from within the caisson directly through the water 35 which will ll the dredge wells as the excavation progresses and the caisson sinks.

, Both methods now in use have advantages and disadvantages, and my invention combines their advantages and eliminates the disadvantages, as will be shown presently.

The resistance encountered in sinking a caisson is due to three separate and distinct forces:

. l(a) The frictional resistance of the vertical sides.

(b) The force of buoyancy due to its water displacement and, when air pressure is used, the pressure of the compressed air on the projected area of the working chamber.

(c) Bearing of the bottom of the wall on the ,unexcavated material.

In the compressed air caisson men are able to work directly under the cutting edge and remove all material under the wall perimeter and thus ,effectively remove the force of bearing from inhibiting the sinking of the caisson. This is not possible in the open dredged caisson as excavation from above can only be done within the area of the dredge wells 26, 27 and 28, making it necessary to dig as close as possible to the walls of the dredge well within the limitation of the size of tlieexcavation tool operated from above.

`-dated clay and hardpan with boulders than it is with the grab bucket or any other surface exca- Since access to the bottom is available, it is therefore easier to keep proper line and grade of the compressed air caisson by controlled digging at the spot.

However, the compressed air caisson has a much greater uplift due to the force vof buoyancy of the air pressure over the entire projected area of the caisson than the open dredged caisson which has a net uplift due only to the displacement of its walls. In large caissons, the open dredged caissonsrrepresent as much as 60% to l'75% decrease in uplift forces over the compressed air caisson. With an open dredged caisson it is also possible to pump the water out of the dredge wells to a lower level, thus decreasing the displacement of the Walls and in this manner-decreasing the buoyancy still further.

The open dredged caisson can be sunk to greater depths than the compressed air caisson since there isA a limit to the air pressures that men can work under (50 lbs. per square inch or approximately 115 ft. of water). Since no men work at the bottom the open caisson can be sunk to any depth required provided the bucket" lconcrete filled walls 40.

can continue to excavate the material at the greater depths.

The main advantage of the open dredged caisson is the fact that material is removed quickly and efficiently without the tedious procedure of passing through air locks. This is often the deciding factor in the choice of this method.

My invention will provide direct access to the cutting edge for men and tools to eliminate bearing resistance without the increase in buoyancy inherent in the above described compressed air method. It will permit the caisson to be sunk to any depths unlimited by safe air pressures of the compressed air caisson and still provide access to the cutting edge to men and tools at this greater depth. The use of my method combines all the virtues of the compressed air method together with the prime virtue of the open dredge method of using the bucket without the necessity of removing excavated material through air or muck locks.

In addition my invention provides for positive means of reducing the skin friction against the sides of the caisson which neither the open dredge nor compressed air method can do.

In brief, my invention reduces skin friction, buoyancy and bearing resistance to an absolute minimum, which heretofore has never been done Vin one combination.

To illustrate my novel constructions and method to be used in the sinking of caissons Figs. 4 to 8 show plan and sectional views of caissons similar in size and shape to that of Figs. 1, 2 and 3 but which incorporate my novel cutting edge working chamber, generally indicated by the numerals 36 and 36a in its two respective modifications.

To illustrate first my compressed air cutting edge working chamber and the methods involved in using it and referring to Figs. 4 and 5, 31 is the outer skin wall of the caisson and also the external wall of the cutting edge Working chamber 36, and 38 is the inner skin wall of the caisson and the inner wall of the cutting edge working chamber. As will be seen the working chamber 36 is conned to the perimeter of the caisson walls only. The roof 39 of the working chamberfis at the same time the lower limits of the concrete filled walls 40. The struts 2| (Fig. 4) .are the same as in Fig. 1 and they are above my cutting edge working chamber 36. The

Vdredge wells 26,' 21 and 28 also are the same as in Figs. 1 and 2.

Referring to Fig. 5, 4l is an access shaft to th cutting edge working chamber 36, and 42 is the air lock through which men and tools can enter and leave the working chamber. It can be seen, that, since the working chamber 36 is directly beneath the walled perimeter of the caisson and approximately the same width as the concrete filled walls thereof, the air lock 42 and connecting shaftway 4| are vwithin the confines of the The dredge wells 26, 21 and 28 are left completely open to the access of a grab bucket or other excavating tool'while the area Ybeneath the caisson walls and along the cutting edge are directly accessible to men and tools. With this construction sinking is performed in the following manner. Excavation of the material is' done from above by the grab buckets 34, or similar tools, directly'through the water which is shown at a level 43 above the AVinternal edge 4 4 of the working chamber. YThis "dredging lrthrough the water covers the entire area of the dredge wells.

Men with theirtools enter the cutting edge working chamber 36 through the air locks 42 and access shaftways 4l and dig the material at the cutting edge and beneath the caisson Walls. The working chamber-315` is kept under an air pressure suii'icientl to balance the internal hydrostatic head 43 within the dredge wells. The material dug by the men in the working chamber 36 is not removed 'through the shaftways and air locks as nowA is the case with caissons of the type of Fig. 3, but is pushed under the bottom edge 44 of the inner Wall 38, directly into the dredge wells 2%, 2'!

andA 28 where this loosened material is readily grabbed by the buckets 34 and removed to the surface. Powerful water or air jets indicated at 45, may be used as an aid to wash this loosened material to a location convenient for removal by the surface excavating tools. Fig. 5 shows` the bottom edge 4E of the outer wall 31 lower than the inner bottom edge 44, so that the outer edge will always be buried in the bottom materiales a seal to the outside, while the material from under the caisson wall is being shoved into the dredging wells. Of course, this leading edge is to be adjusted to a height depending on the Amaterial expected to be encountered and in many cases it would be just as feasible to have edges s and 46 at the same elevation.

Should the material be of a hard nature, such as the consolidated clays or hardpan with boulders, as mentioned above, so that it is diilicult, if not impossible, to dig it in its natural state with a surface excavating tool, such as the bucket '34, such material can nevertheless be excavated unconsolidated state readily excavated by the bucket 34 operatingthrough the water.

As will be described hereinafter, in connection Awith my free air or atmospheric working chamber, the jets shown at 41 can be used through my novel valve and stufnng box unit, so that all Vthe horizontal work above described may be done through the inner wall 38, instead of below the edge 44. In addition the earth which is removed from the bottom of the working chamber 36 can be discharged through the skin wall 38 into the dredge wells 26, 2'.' andv28, by means of a mud pump or air lift operated from within the chamber by my said novel method to be described presently.

Since the air pressure in the working chamber 36 need only be sufcient to balance the hydrostatic head within the dredging wells 26, 21 and 28, it is obvious that by lowering the level of the 2 -by a blast so that the material will be put in an water within the dredge wells of the caisson, the

necessary air pressure in the working chamber may be reduced. This is of great advantage to the men in the work clhamber as with the lower pressures men can work safely for longer periods.

In addition, as has been mentioned above, there is a safe limit of 115 ft. of Water or 50 lbs. per square inch air pressure under whichY men can work. Therefore the present compressed air method, as described in connection with Fig. v3,

has Vbeen limited to approximately thisfhead. However, no such limitationV exists with mymehod, for by placing a pump 48 with its discharge line 49 in a dredge well, the water level can be lowered to.a lesser head 50, thereby reducing; the necessary air pressure for this lesser head, while Vthe external head 43 may be much greaterthan lthe limit [head of H5 it. Limitations to depths sunk with this form of my method areronly fune- -tions of the capacity of the pumps used andl the nature of the ground.

As can be seen, all methods known in the art of excavating can be used directly by the men in my cutting edge working chamber 36, in various combinations with all methods known in theart for open dredging through the` dredging wells from the surface.

A comparison with the two presentV methods of open dredging or the compressed air method, as 'has been described in connection with Figs. l, 2 and 3, shows in effect that my method .involves the simultaneo-us use of opendredgingand compressed air operation and therefore provides for the simultaneous advantages of both methods Vwith none of their inherent disadvantages, as--follows:

Men are able to work directly under the cutting vedge and remove all material under the Wall pe` vrimeter and thus effectively remove the force of bearing from inhibiting the sinking of the caisson as with the compressed air caisson of Fig'. 3.

Because of direct access to the material `it is possible to dig all hard materials no matterwhat their nature and thus keep proper line and grade by controlled digging at the spot, also an ad- ;antge of the compressed air caisson sinking of Because the working chamber is confinedl to the walled perimeter the uplift force of buoyancy 1s reduced to the minimum of the water displaced by the walled perimeter, and also since water can be pumped out of the dredging wel-ls the buoyancy can be reduced still further to negligible amounts, now an advantage of open dredged caisson of Fig. 2.V

Because the air pressure in the Working chamber can be reduced by pumping in the dredging Wells, the safe working depths for men under compressed air have been appreciably increased without increase in pressure through my invention and sopresents this advantage.

Because material is pushed out of the work chamber into the dredging wells it is possible to excavate material from beneath the cutting edge without the tedious procedure of carrying the material through the muck locks, this im-l portant advantage now being obtainable only :by the open dredging method of Fig. 2.

In generaL-my novel method possesses all the advantages of the compressed' air caisson, and provides direct access to the material being Aex'- cavated without the disadvantage of muck-ing through air locks, of .greater uplift due to buoy- .ancycaused by the air pressure, and without ing limited to depths under which it canbe used due to limitation of sare working. pressures. ..1 also provide inmy novel lmethod for all the ad- 'vantages of the open dredged Caissonl of being able to reach greater depths, excavating .directly through the water, reducing uplifts to a ,minbmum and without its disadvantages ci having no access to the cutting edge and the .diiculty of digging hard consolidated materials Ythrough .the water. In addition my method, .because QI: the .strategic .location of the. cutting edge wor-kine Work chamber.

the bottom 55 of the work chamber 36a is moved chamber so as to give access to the material which directly creates bearing resistance, without inhibiting the space of the open dredge wells, provides advantages, indicated in the above general description, which no method used at present can provide.

To generally describe my free air or atmospheric cutting edge working chamber, and the methods involved in using it, I refer to Figs 6, 7 and' 8, in which 5I indicates the outer caisson wall and hence the outer wall of the free air working chamber 36a. 52 is the inner wall of the caisson and also the internal wall of the working chamber. 53 is the roof of my free air cutting edge working chamber which at the same time is the bottom limit of the concrete Walls 54, and 55 is the unique structural iloor or bottom of my free air working chamber. As before, it can be seen that this working chamber 35a is confined to the perimeter of the caisson. The struts 2| are as before and likewise are the dredge wells 26, 21 and 28 which are left open to provide free access to the material removing devices. 55 is an access passageway for men and tools which communicates directly to the free air or atmosphere at the top of the caisson. It can therefore be seen that together with the access passageway 56 through the concrete walls 54 and the roof 53, the sides 5I and 52 and the floor 55, the working chamber 36a is a watertight enclosure with direct communication to the atmosphere. This chamber must, of course, be designed to withstand the pressure of the full hydrostatic head, wherefore I employ ribs to be described presently, which are of a size and spacing sufficient to withstand this pressure. The shape of this cutting edge working chamber 36a shown, is of course, not exclusive but is one of the numerous shapes that may be used depending on the type of the material through which the caisson is to sink and .the depths and ultimate structures required.

With my atmospheric working chamber this means of the grab bucket 34 or other surface operated digging tool which will excavate through the water inside the dredge wells of the caisson. Men with their requisite tools enter the free air work chamber 36a directly from the surface by means of the access shaftway 56 without the necessity of an air lock since the work chamber is at atmospheric pressure. No material is dug within the confines of the work chamber since there is no open bottom as in my compressed air Instead the material beneath into the dredge wells 26, 21 and 28 to a location convenient to the grab bucket 34. Excavation, loosening and moving of the material by means of tools operated through watertight stuing boxes and valves, details of which will be described hereinafter, in connection with Fig. 9. My novel stuffing boxes and valves will be so spaced along every foot of the perimeter of the free air working chamber 36a that by employing air'and water jets, drills, dynamite, and other similar tools, and means through these stuffing boxes, the material can be efficiently washed and loosened into a state and location that the bucket will be able to excavate the material away from beneath the free air working chamber and permit the caisson to sink into the excavated area thus provided. These stuing box and valve units are of such nature and size that the usual excavating tools of the type above mentioned can work through them either horizontally or vertlcally, or diagonally, and in effect attack the material as efciently as if the men who operate the tools from the free air work chamber 36a were in direct contact with such material. Since the men, however, operate in free air, the tremendous advantage is at once apparent of having men at the cutting edge, no matter what depth the caisson is to be sunk to, without having them subject to the inherent discomfort and dangers of compressed air, and still be ableV to perform all the functions previously performed only under compressed air, and at the same time to excavate and remove the material easily through the water by open dredging. y

All the advantages described above for my compressed air cutting edge working chamber also apply to my free air cutting edgeworking chamber. over the methods heretofore used in the art of building and sinking a caisson, with the addition of being able to have men and tools operate in free air at a cutting edge subject to a hydrostatic head, which was never done before. In Figs. 4, 6 and 8, at 51 I show by dotted lines, bulkheads which can be placed in both types of Working chambers between the respective access shaftways. These bulkheads can be opened or closed by watertight doorways as desired', so as to cut off one section of the working chamber from another. This may often be desirable to concentrate excavation at a particular location or to control the buoyancy of the caisson by filling a particular chamber with water in order to rectify a tilt or shift in line and grade developed during sinking, or while setting a caisson on the river bottom during its initial placing at the sit where it is to be sunk. l

In connection with the process of floating a caisson in the water before setting it on the bottom in preparation for sinking through the earth, it should be noted both in the case of the compressed air and free aii cutting edge working chamber that the buoyancy of my working chamber is at the lowest tip of the caisson, wherefore a caisson with such construction can often be iioated into place with less displacement in depth than now is usual with open dredged caissons. l In Fig. 9 I show my free air cutting edge working chamber 35ar in a larger scale, shown diagrammaticaliy and more in detail. In this ligure the parts hereinbefore mentioned are indicated by the same numerals. At 58 I show a walkway within the work chamber. The mentioned valve and stufng box assemblies are indicated' at 59 and 60. n v Referring to the assembly indicated at 59, the numeral 6i represents a plug cock valve, or similar valve, which when open leaves the valve chamber completely clear and 52 is the" handle by which the valve is opened or closed. VEsuch valves are well known in this art. 63 is a pipe or casing which is threaded into the bottom flange of the valve 6l and welded to the oor 55 of the working chamber over an aperture thereon, so as to form the opening 64 of a diameter preferably equal to that of the pipe S3.y Threaded to the upper flange of the valve 5| is a pipe or casing 65 of a size approximately equal to the free diameter' of the valve Bl When fully open. Attached to the top of the pipe 65 is a watertight stufng box 66 of a type used in all marine work and well known in this art. The stuffing box will allow a shaft or other similar device-to pass through the same, enter the Water .at its outer end and yet be in the working chamber in the'dry :at its other end. This combination of the valve 6|, which is connected to the outside of the working chamber by means of the pipe 63, is the means by which Amy invention makes it possible to have men operate tools within the Working chamber while the digging, drilling, setting, excavating, blasting, etc.; ends of the tools outside of the working may attack the material that is to be excavated.

The assembly at 59 Shows an air drill .being used through the valve 6| and stuing box 66 to drill a hole Si in the rock 68 beneath the working chamber While the similar` assembly at 6G shows a pipe casing being used through the valve and stuffing box to load dynamite and blast vthe rock previously drilled by the air drill of the assembly 59. A brief description will ilulstrate the method by which these tools are used.

Referring now, again, to the assembly at B,

68 is a high pressure air line connected to a mani ifold 'i0 which runs along the roof 53 inside the work chamber Sta and which, in turn, is connected to a surface compressor plant by means of the pipe line 'l l, brought to the working chamber from the surface through the access passageway 56. The valve 6| is normally kept in a closed position when vit is not in use. The bit end l2 of the drill steel T3 is rst inserted through the stufling box 66 so that its tip passes through the stuffing box 66 into the casing 65.

In case the bit end 12 is over large. the stuiiing box e6 can be disconnected from the casing 65, the shank end 13 inserted into the stuiiing box from below and then the stuing box reconnected to the casing 65 so the bit end 12 will n enter the casing 65.

The high pressure 'air is then turned on by opening la respective valve on the 'manifold T0 which permits air to iiow through the line lill into the casing 65 where it is trapped by the stuiiing' box '66, at one end, and the normally closed valve BI at the other. While the casing 55. is still under Vair pressure the valve 'l is opened by the lever 52. The air then rushes through'the valve, the small pipeway 3, out through the 'opening '64 into the material beneath the working chamber 38a Aso as to provide a clear passageway for the tool to follow.

. After the way is cleared, the air may be out oi, or left on, as conditions require, the drill steel is pushed through the valve 6l and the opening E4 into the material beneath the working chamber. The rock drill T4 is then attached to the shank end of the drill steel "I3 and connected by means of the air hose "l5 to the air manifold il). The drill is now ready for use. Its tip or bit 'l2 is 'outside the Working chamber and in the Water saturatedground, while its shank "i3 has passed through the watertight stu'flin'g box and is connected in the dry to the drill 'I4 within the free air working chamber 36a. The drill can now be operated as it ordinarily is used when drilling through water. .Assembly 59 shows the drill after having drilled the hole 61 in the rock 68.

Referring now to assembly 58, 'I6 is .a pipe (shown in the `drawing as 4for the loading and blasting of dynamite) which is passed through the stuing box 65a, the casing 65a, the valve Ei la, the short pipe 63a, and aperture 54a by the method outlined in the example of the drill steel used with assembly 59. H isa similar but smaller valve attached to the top of the pipe i6. This valve 'Il is closed when the .pipe '16 is passed through the stuing box 66a. Over the valve .'l! issecured a pipe or casing 18 being similar to the casing 65a attached to the Valve Bla, but, of course, also being of smaller dimensions. Casing 18 has connection to the compressed air manifold 10, as by the pipe line '19, and has a stuiling box arranged at its upper end, said stuffing box, again, being similar to the stufng box 66a but smaller in size.

After the pipe i6 is passed through the valve 5 la and the bottom of the working chamber into y the outer material, the respective valve for the compressed air line 19 is opened, as well as the valve 11, whereby the air will enter the pipe 1B and clear all possible obstructions out of the pipe, but discharging through pipe 16 into the material beneath its tip.

Now a special dynamite loading pipe 8| is prepared, the lower end 82 of which carrying the dynamite charge in an appropriate manner, as it is wel-l known in this art. Pipe 16 will be lowered to the top 0f the hole .Ela drilled in the material to be blasted.

The dynamite carrying pipe 8l will be passed through the stuiiing box 80, casing or pipe 18, valve Tl, and down through the pipe 16 into the hole 51a., as indicated in Fig. 9. The blasting Wires 83 all the time are disconnected, but when the dynamite is in place, pipe 16 will somewhat be Withdrawn while the dynamite carrying pipe 8 l is held stationary so that only the comparatively light dynamite carrying pipe will be in the drilled hole 61a, whereupon the wire 83 will be connected to the exploder mechanism 84 and the dynamite exploded.

There are many occasions when it will be expedient to use pipe 1B as an exploratory pipe, following which exploration it would be convenient to operate a drill or jet through it. To do this, the end of stuffing box 80 is plugged, the valve 'l1 is opened, the air pressure is applied through the air line T9, and the pipe 16 is used for exploratory operations outside the working chamber, like an ordinary blow pipe, a device well known in underground operations. Then when the blow pipe locates an obstruction it can be le'ft in place and the drill steel, or jet, or other tool, can be inserted through the stuing box 80 and can be used passing through the 'blow pipe 16, as will be obvious from the description of similar operations hereinbefore.

It should be noted here that drill holes 85 and 86 are shown drilled on a slope, while the assemblies 59 and B0 indicate the operation of a tool vertically. As mentioned above, the valve and stufling box assemblies are located along the free air cutting edge working chamber at a spacing to be determined so that the entire area beneath the working chamber can be reached by the .probing tools operated from within. Some of these valve and stuiiing box assemblies are therefore mounted vertically as at 59 and 60 in Fig. 9, some will be mounted horizontally, as indicated at 8'! and some may be mounted at varying angles with the vertical, as for the sloping holes 85 and 86.

In Fig. 10 I illustrate how the whole valve, casingr and stuliing box assembly may be mounted on a ball and socket joint in its connection to the wall or iioor of the cutting edge chamber. Such a construction is most useful in a kmaterial where a great deal of angular work might be required. When using this construction the whole assembly, tool and all can be rotated to whatever angle is required without recourse to another valve and stuingxbox unit. In .said figure Bib is the valve, Blifthe com- 11 pressed air casing, 56h the stufng box, 64b is the opening in the floor 55 and 88 indicates in general the ball and socket joint for the valve, such valves being well known in this art. The dot and dash lines 89 and 9] indicate the center lines of the device at two angular positions.

In order that the men working within in my free air Working'chamber can see into the material outside of the same, a special valve and stuing box unit may be used, as indicated in Fig. 11. The valve 6|c rst will be closed and the stuffing box earlier described will be removed from the top of the casing 95e. In its place a transparent glass plug 9| is secured into the casing 65e. The air pressure is then turned on by means of the air line 690 and the valve Slc is then opened by means of the lever handle B2C. The air stream will then enter the excavated area below the sight glass 9| and by using a powerful light 92, men in the working chamber will be able to view the exterior material by looking through the sight glass plug 9| and out through the opening 54e. In a .modification of this operation a powerful light can be lowered through a blow pipe 'I6 arranged in a valve and stuffing box unit described, preferably of the ball and socket type, and thus a light is placed directly into the excavated area. When using this. method the light 92 may be extinguished and an unobstructed view of the bottom can be obtained by using the viewing glass 9|. As will be understood a light can also be permanently attached to such a pipe 'I6 thus forming a light pipe and used through a valve and stuing box unit whenever the occasion demands.

v .From the above description it can be seen that my valve and stufling box unit, as described, can have many combinations of uses, as it provides in one construction a positive waterproof cutoff to the outside, i. e. the closed valve, and a positive waterproof access opening to the outside, i. e. the open valve backed up by a compressed air casing and a stuffing box. It is clear therefore that by using water or air jets, drills, blow pipes, dynamite, glass plugs, light pipes, and other requisite devices, through my valve and stuffing box unit, it will be possible to move any material beneath the free air cutting edge working chamber into the dredge wells where it can easily Ybe removed by a grab bucket or the like operated from, the surface.

Referring once more to Fig. 9 the numeral 93 indicates a water pipe riser connected to jet pumps at the surface and 94 is a manifold along the roof 53 of the working chamber. a jet is to be used, a jet pipe with its properV nozzle is inserted through a stuffing box and valve unit, a hose connection made to the manifold 94, its valve opened by men in my free airwork chamber and the jetting operation is carried on as desired, the men being able to view the results of their jetting at the spot by use of the sight glass 9| in combination with a light pipe inserted through a nearby valve and stuffing box unit. Such an operation is a tremendous advance in the art of jetti'ng, because heretofore the jet pipe has always been shoved into the earth, and beneath theY water where it was impossible for anyone to view the results of the operation. Because of the strategic location of my cutting edge working chamber,v together with my exible valve and stuffing box combination, it is possible for men to, work in the comfort of normal'atmospheric presv sure and control the actions of a Water jet by Whenever i12 actually looking at what is happening instead of guessing as has been the case heretofore.

In addition one of the basic troubles involved in jetting is easily avoided. When Working in the earth a jet is always likely to .become clogged at the nozzle end by the material in which it is immersed. Usually such jets are fixed to the caisson and when they are clogged, since they are inaccessible to cleaning at the nozzle end, they go out of service. With my method of inserting a short pipe through a valve and stuiiing box unit, should a water or air jet become plugged, the jet lpipe is withdrawn through said unit, the Valve closed, the jet pipe pulled into the working chamber, and the plugged material removed from the nozzle end. When the jet pipe is thus cleaned it can be reinserted through the valve and stuffing box and put back into service. Very often when caissons are to be put through sticky clays or similar dense material, the use of jets is discarded because of the repeated experience of knowing they will become plugged in such ma-l terial and thus be useless. With my method, jets, which are one of the most eflicient means of moving any kind of material, are not subject to this often disqualifying objection.

It should be noticed also that a Water jet as described hereinbefore, used in connection with an air blast emerging through one of my valve units forms the most explosive combination of air and water known in the art of jetting.

In Fig. 9 I also show, at 95, a riser pipe to the surface, and at a manifold which, like the others, runs along the roof 53 of the cutting edge working chamber and around the entire per# imeter of it. This riser is connected to ay high powered sludge pump located at the surface. 'If desired the'sludge pump can be operated from within the working chamber in which case it is directly connected to the manifold 96. Into this sludge pump is placed a mixture of slippery clay and water, such as bentonite, and this mixture is pumped down the access passage 55 throughthe riser 95 and into the manifold 95. 91 and 98 are flexible hose connections to the pipe ejectors 99 andl. These pipes are inserted through two of my valve and stuffing box units, ||J| and |02, as has been described. By opening the requisite valve on the manifold 96, the clay and water mixture |93 under pressure from the surface pump will ow through the hose lines 91 and 98 and into the ejector pipes 99 and |00, which are inserted through the stuffing -box ,and valve units IDI and |92 into the material adjacent to the vertical side 5| of the caisson. Together with the air blast brought to these valve and stuffing box units through the hose lines |04 from the manifold l0, if required to loosen the original material next to the vertical side of the caisson, the ejector pipes can be efficiently used to deposit a layer of slippery clay |03 alongside the skin wall 5| of the caisson. Since these valve and stuffing box units may be spaced along the entire perimeter of the caisson, a uniform coating of this mixture can be placed in the original ground as the caisson passes through it. By using the sight glass plug 9|, alone or in combination with a light pipe described hereinbefore, through a nearby stuffing box and valve unit, the progress of this clay depositing operation along the skin wall of the working chamber can be observed and controlled. y

As the caisson sinks this slippery clay deposit remains in the original ground-'and thus 'th enti-refoute'r skin wall-from top to bottom will asseoir 13 pass through, wand always willbe in contact with, the clay `deposit |03. Such a deposit of slippery material on the 'outside of the caisson will reduce the skin 'friction to a ynegligible famount.

As discussed with the water jet, hereinbefore, the -plugging of the vejector end of a sludgezpump is very common, but when itis used combined with an air jet through my stuffing box and valve unit lthis diiiiculty can be eliminated.

It should 4be noted that 'if .the access vpassage-- ways 56 for men and materials were placed against the outer skin wall 5 l, as shown at 55a in Fig. :8, instead Vof in the center of the concrete Wall A54, it is possible to place several 4of my valve and stuiing box units at diierent levels "along these free air access shafts156'a. From these supplementary valve and stuiling box units, the results of the depositing of the clay at the Working .chamber level may be Vobserved 'and any` supplementary deposits of yclayrequired can also be placed through the same in the manner clescribed. This 'combination of free .air cutting edge working chamber with its access to the `out- Y side through my novel combination of valve and stuffing box permits'a positive method of depositi ing clay against the outer skin wall of a caisson to reduce toa minimum the skin frictions which inhibit vthe Asinking of a caisson. The ejector pipes .99 .and H10 may be moved, inwardly or outwardly, etc.; to aid in depositing of Ithe clay.

.I have shown .how `rny novel methods and con structions 4provide positive means for bringing to the lowest minimums the three inhibiting forces against sinking, that is, the skin friction,

buoyancy, and :bearing under the cutting edge,

a result which no other method used heretofore can show.

It Ashould be noted that jets as indicated .at 41 (Fig. A5) in connection with my compressed air cutting edge Working chamber 3B may, of course, be operated through my valve and stuffing box units .as shown in Fig. 9.

When .the caisson is sunk to its iinal depth as required, usually a .seal is .made to the bottom strata. often the case, men working in the compressed air Working chamber 36 `(Fig. 5) can clear ofi?A all .the loose material from the rock. Then Vconcrete may be .placed on the :door of the working chamber to create a seal Ato the rock between r.:

the outside water and material and the outer skin wall 3! of the compressed air Workingchamber. A foundation can be built under the cais- 'son wall and, .if required, the entire compressed fair cutting edge working chamber 36 can be :r

lled with concrete, the lock 42 removed and the shaitway 4| also ll'ed with concrete. After the seal to the rock is made the dredge wells 25, 21 `and 28 can be pumped out, and whatever vstructure is to be built within the confines 'of the caisson can be nnished in the dry.

Should the bottom be some 'hard ear-th strata, as is sometimes the case, va Aseal to this bottom strata is likewise made, and the Working chamber i'llled with concrete to provide a broad ibase to make the most eiiicient seal possible, the dredge wells pumped out and the internal structureiinished in the dry.

With the free Aair cutting edge working chamber, when the caisson is brought to its final f depth as shown in Fig. 9 by its close proximity to the rock ledge H16, `the rock is .leveled oil driling and blastingI as required through the vave and stuffing box assemblies-53 and Bil.. .'Ihel AIt the .caisson is brought to rock, as is .rcckis then, cleaned yby means of blowrzipes and.

114! Y, '-jet pipes operating through vmy valve vand f' ufflng box assemblies `and then after the rock is leveled and cleaned, 'grout, concrete or other materials are ejected through the blow'pipes operated through valve and 'stuffing vbox units. By moving the grout ejecting pipes in all directions as reouired, und-er control of operators working with blow pipes for sounding, and sight glasses combined with light pipes, the sealing 'materials can be placed so as to form a seal between the rock 'and the bottom 55 of the free air Working chamber 35a, and at thevv same time provide a foundation for the caisson as Wella's afseal Yagainst tfe outside water and earth. The dredge lwells 25, v21 and 28 can then be pumped clear of water and the iinal foundation nishe'd as before, in the dry.

vShould the iinal foundation require a type of open construction beneath the cutting edge, a sec-*ion i0? ofthe bottsm 55 (Fig. 9) can be made removable by disconnecting the bolts |08 which secure the removable bottom I U1 vultimately t0 the sides "5I and 52. Air locks can be placed on tops of the access Ways-5B, compressed air introduced into the working chamber 35a before the bottom p'ate is removed, wherefore the bottom seal -can be made under compressed air as described hereinbefore 'Should the free air working cham er be of the bevel shape shown in Fig. 9, tren bori-ontal or vertical sheeting H0, shown by dotrand ydash lines, can be carried down to rock and the nel foundations finished as described for the vcompressed air cutting edge Working chamber. In the `process of reaching the rock, steel ,plae sheeting Hl, previously attached to the wal c'f the 'free 'air Working chamber, can be driven through a slotted -stuiling box at I I2 ftbu'ilt between the vertical reinforcing ribs H3 and sections of the floor 55 between them) down to the surface of the rock, and into it if required, with the help of jets and drills operating through my valve and Astuilng box assemblies 59 and |J. 'When the 'bottom o'f the free air cutting edge working chamber is founded on an earth stratum, Agrou or other materials, 'such as bentonite, can be ejected through valve and stuiiing box assembl-ies :to consolidate the bottom in the vicinity of the entire free air cutting edge chamber, andthus Vvform vthe best possible Lfoundation in the earth stratum. Following this `the dredge wells `can be unwatered and the interior foundations finished.

Very often, es in bridge foundations on earth strata, the .dredge Wells are not unwatered but the fdredge :wells are lled with concrete through the water by the tremie method. With my cutt'ng vedge working chamber, by constructing valve and stufling box units 'of a proper size, concrete or other iiling can replaced bypumping directly on the bottom without the necessity of using the tremie'rrethod.

If `desired the free air cutting edge Working chamber together with its access passageways ycan be 'lledwith concrete after the seal to the bottom is made.

Whie the above descriptions have been com mrd to rectangular caissons sunk by their ovfn wel ht duringexcavation, my cutting edge working chamber, yboth the `compressed 'air Aand the atmoipheric or free air type, can be used equally eiciently 'in large circular caissons which possess concrete filled walls to provide the weight for sinking. In fact the'cutting edge Working chamber can be made in any shape required, so as to follow the .Perimeter or `rolltours ogfzthe ,ternally as shown in the section of Fig. 13.

' My free air cutting'edge working chamberA has a particular use in the sinking of smaller cylinders, constructed without concrete filled walls, and which are sunk into the ground by driving from the surface with a power hammer. Such `a use, as will be described presently is to my knowledge,V a most revolutionary andl novel 4method for the sinking of small caissons (both cylindrical or rectangular) inasmuch as men and tools can have access to the material' at the cutting edge while the driving Yhammer is operating at the surface, thus performing simultaneous sinking due to the driving force of the hammer and excavation due to the operation of the men and tools in the Working chamber below.

Referring to Fig. l2, lid is the caisson (cylindrical in this case) vwhich is to be sunk by the power hammer H5. The blow of the hammer l5 is delivered to the cylinder H4 through the vdriving cap H6. Il' is my free air cutting edge chamber formed by the exterior skin wall ||8 of the caisson and the interior wall I9 of the cutting' edge working chamber (Fig. 13). |26 is the oor and |2| the roof of my free air working chamber. This working chamber is constructed to withstand external pressures and is braced and ribbed for strength similarly to the free air Working chamber 35a described hereinbefore. |22 are valve and stuffing box units of the type described. |23 is an access passageway from the surface to the working chamber Il?. |25 is a driving cylinder of exactly the same size as the cylinder H4, and which joins it at a bearing connection |26, flanked by thesplice plates |27, so arranged that the .blow of the hammer will be transmitted through the cap I and the driving cylinder to the caisson ||4 which is to be driven into the ground.` This driving cylinder is constructed so as to allow the men and tools to enter within the caisson ||4 and pass through the access shaftway |23 to reach the working chamber Il below. To achieve this an access hole |24 is arranged in the driving cylinder |25 so as to provide a -connection between the exterior and the interior as described. |28

-is a pipeway through which the excavated material is removedP and may be formed at the bottom by the interior-wall IIS of the free air cutting edge chamber IVI. The pipeway |23 passes through the driving cylinder |25 in a similar manner to that shown by the opening |24 for the access passageway |23.A Splice connections between the upper and lower ends of the respective sections of the access passageway |23 and the exhausty pipeway |23 will be made as shown at |26 for'the caisson ||4. These splices do not in any way carry the blow from the hammer I5, it is delivered only through the wall of the driving cylinder |25 to the wall of the caisson |I4. Hose connections for delivering high pressure air for the excavating tools in the working chamber, water lines for jetting, and pipeways for delivering clay and water mixtures to the working chamber, electric power lines, etc., can be carried down within the 'access passageway |23, if the access passageway is large enough, or ex- In said section |30 is a high pressure air line, 3|

a water line for jetting, |32 is a pipe line for clay and water, and |33 is a conduit for electric power lines. .These lines are brought through the driving cylinder in the manner described hereinbefore. 7

-'- 'Sinking of the cylinder is performed as follows:

16 The hammer l5 transmits its 'blow through the driving cap H5, the driving cylinder |25, to the caisson H4, causing the bottom tip |34 of the cutting edge to move vertically through the ground. As the caisson moves into the ground the material vbeneath the cutting edge will develop bearing resistance to counteract the driving, and the material along the verticalsides will develop skin friction which will also cause a force counteracting the driving. To remove these two forces, men -with their tools enter the access passageway |23 through the opening |24 and descendV to the cutting edge working chamber Hl. By means of valve and stuing box units |35 and the pipe line |32 connected to the sludge pump on the surface, 'slippery clay and Water.

mixture can be ejected into the material along the vertical sides of the caisson I4 by the methods described, thus decreasing the frictional resistance. Compressors and jet pumps at the Isurface deliver air and water under pressure to manifolds in the working chamber through the pipe lines |33 and |3|. By methods already described, using my valve and stuffing box units 22 for the air and water jets, the material inside the caisson `cylinder I4 can be loosened and putin a saturated state. Since the tip |34 of the caisson is driven into the material alongside and beneath the cutting edge working chamber the water and material will rise through the exhaust passageway |28 which provides an exitway with the least resistance. In eiect by ejecting air and water into the passageway |28 at its lower end, an air lift is formed which will carry the Water and earth in solution up through said exhaust passageway for discharge above the surface. While this will be the most usual method for removing the material loosened and placed in saturation by the men operating the requisite tools through the valve and stung box units in the working chamber, any other means of moving this excavated material from ythe base of the working chamber can be used. For example, a sludge pump |36 can be lowered down through the pipeway |28 and the material agitated by the men operating in the working chamber can be pumped directly to the surface for disposal. Other means such as orange peel buckets, hailing buckets, endless belt excavators, etc., can be used to remove the material excavated by the men in the free air working chamber. The pipeway |28 can be omitted if desired, and the inside 0f the caisson l|4 will then become the exhaust chamber for removing the excavated material. The pipeway |23,'or its' equivalent, in effect becomes a dredge well similar in use to the dredge wells 25, 27| and 28 mentioned hereinbefore and therefore all the operations already described in connection with my cutting edge working chambers can be similarly performed and the material similarly removed. However, the nature of the restricted area of the pipeway |28 presents the opportunity of using an airlift in connection with jetting air and water through the valve and stuffing box units |22, which is one of the most convenient methods of excavating earth known in the art.

Thus by excavating, as described, the material beneath the free air cutting edge working chamber lll is removed, the bearing resistance decreasedg'and the cylinder can be drivenl through the ground' by the action of the hammer H5. Should', boulders ,be encountered, they can be drilledand blasted throughy'my valve and stuifing boxlunits and thus pulverized for removal.

When the iinal strata is reached, which in the case of the smaller cylinders is usually rock, the bottom is cleared of loose material, leveled off, the cylinder driven to bearing on the rock, and a grout seal placedwithin the cylindrical caisson on top of the rock to make a Water cut off. The caisson can then be unwatered and lled with concrete if (as is usual) it is to form a foundation pier, or following unwatering any structure can be built in free air inside the caisson. The free air Working chamber can be removed if desired before placing the concrete ll, or `can itself be lled with concrete and left within the permanent foundation. Thus all operations of driving, excavating, reducing skin friction by claying up the sides, sealing the bottom, and building the final foundation, can be done with my free air cutting edge chamber equipped with my valve and stuiiing box units.

What I claim as new and want to protect by Letters Patent of the United States, is:

In an underground closed working chamber, the combination of, a normally closed valve secured on the wall of the working chamber at the inside thereof, said valve being adapted to be opened and then provide a passage from the inside of the working chamber to the outside, a casing secured on said valve, connected to a source of compressed air and adapted to communicate with said valve, and therethrough to the outside when the valve is open, an opening being provided in said casing opposite to the opening of said` valve, a stuiling -box in the opening of said casing adapted to permit a sealing sliding of a desired elongated instrument therethrough, means to control the entrance of compressed air into said casing, whereby the compressed air may be shut off from said casing and said instrument partly inserted through said stumng box thereinto, then the valve opened and the compressed air permitted to pass into said casing and through said valve to the outside, and then the instrument advanced through the stuifing box, the casing and the valve to the outside, said instrument having an inner controlling end portion projecting from the stumng box, said inl strument being in the form of a pipe passed through said stuiiing box, said casing and said valve, from the inside of the working chamber to the outside thereof, a second normally closed valve secured on the inner end of said pipe, a second casing connected in a controlled manner to a source of compressed air on said second valve having a co-axial opening therewith, and a second stuffing box in said co-axial opening adapted to permit an elongated second instrument to sealingly slide through said second stuffing box,

through said second casing, and through said second valve, and through said pipe to the outside under an outward air pressure.

CHARLES GOODMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

